From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id AC4EF428857 for ; Fri, 15 May 2026 10:01:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778839268; cv=none; b=IZAxfv4MT/JNsDMxE+59QQj4d1RwHPcAGnrthfErUkKdaoeoELbN/iD2CTL4JGRkGZeU82FQmI76wJB3KlqY5sVpoS8KZN3yS9f1rK6zLDcblnWdarcxCryMOQKIKdCOhR9kdD4xkazDsVBZquTl3y5F7CsZIa4mc7L3MgJ5ey4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778839268; c=relaxed/simple; bh=0qWqSKPyVhACVypG4ggtLdOrmJFtIKEKXkeH46W8rzY=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=DdBEDi5s4HyWRwn8B0FMdhezUHfFAfe/ogN7PbFVhkoBAR70sELZ0pzezHeJ7+gRdRwLeV/Mgne3Tvqxcz1qIafoAHsoB2xWjwB2yNTbVlHLwIBuzCEo2rlPT56A+9ix0rK4OAXIFKNQQUDh9FNxGDzgr7Op3jZsjjlaER8dNgc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b=crYxWU5I; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b="crYxWU5I" Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 8BE692574; Fri, 15 May 2026 03:00:59 -0700 (PDT) Received: from [10.1.32.25] (e127648.arm.com [10.1.32.25]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 951FB3F85F; Fri, 15 May 2026 03:01:02 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1778839264; bh=0qWqSKPyVhACVypG4ggtLdOrmJFtIKEKXkeH46W8rzY=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=crYxWU5IrVThH3wSi+Mk2VXXRzxV3HMyWv6Sj0x0U1SQ45j5G0VvXgCb8coUtJ8rB eEaUIpdrLca7tMTbqitLWISO2Gi5Uu3vuQj+PnbnYX/irQ3QK8i+aUMWrQWMW5M1Od Ypww8JHhpDOQguGtusWEVmgbyu27CYxWvGMKuF6M= Message-ID: <28c59186-4ba0-44f4-b5b8-42f6f73cd3e6@arm.com> Date: Fri, 15 May 2026 11:01:00 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 00/13] sched/fair/schedutil: Better manage system response time To: Tom Gebhardt , Qais Yousef Cc: linux-kernel@vger.kernel.org, Peter Zijlstra , Ingo Molnar , Vincent Guittot References: <20260504020003.71306-1-qyousef@layalina.io> <20260515014250.tueinbuk7ldttdop@airbuntu> <32dea9123588227a02971341b22e84d3.tomge68@gmail.com> Content-Language: en-US From: Christian Loehle In-Reply-To: <32dea9123588227a02971341b22e84d3.tomge68@gmail.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 5/15/26 09:24, Tom Gebhardt wrote: > Hi Qais, > > Thanks for the follow-up. Here are the patch isolation results and answers to your questions. > > Regarding the governor: > > Yes, I'm running `ondemand`, not `schedutil`. My mistake for not mentioning that upfront - I > assumed the improvement was due to the util_est path being triggered regardless of the governor. > The improvement is clearly measurable even with `ondemand`, which is surprising given that your > patches specifically target `schedutil`. Something is wrong, as Qais mentioned raspberry pi (SMP) with ondemand shouldn't be affected by util_est changes. In particular with 4 mostly-running workers and 4 CPUs. Does patch 12 also show similar effects with powersave/performance cpufreq governor? Qais also split patch 12 out separately and Vincent posted a fix, care to give that a try? https://lore.kernel.org/lkml/agRyoe1wHyZ-vMk9@vingu-cube/ Thanks for testing these, I'll try to reproduce what you're seeing, too. > [snip]